# Unknown Ventilation System **URL:** \ **Category:** General Inspection Topics\ **Created:** [November 18, 2024, 9:38pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203 "2024-11-18T21:38:39Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![mjorge2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mjorge2/32/250241_2.png) [@mjorge2](https://forum.nachi.org/u/mjorge2)\ **Post date:** [November 18, 2024, 9:38pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/1 "2024-11-18T21:38:39Z")
Hi, just started inspecting and I found a ventilation system that I have never seen before. I am not sure what it does or why but I found this in a house in central CA. I tried to turn it on but couldn’t hear or feel any air movement. Does anyone have information on this? ![IMG_3244](https://global.discourse-cdn.com/internachi/original/4X/c/4/8/c480291e994a92c4a392cfd8eba702c0a098417b.jpeg) ![IMG_3245](https://global.discourse-cdn.com/internachi/original/4X/e/b/a/eba7c26e54262ba87a92ea0c79167a897c84d9f7.jpeg) ![IMG_3246](https://global.discourse-cdn.com/internachi/original/4X/d/0/3/d039ad9da7d64d20ec62804eef24a8e31925b55e.jpeg) ![IMG_3247](https://global.discourse-cdn.com/internachi/original/4X/e/8/3/e8338b7e49f0df441f3f146e5906c79fc925d7c6.jpeg) ![IMG_3248](https://global.discourse-cdn.com/internachi/original/4X/0/c/6/0c65ad7dc031a7c9e852f4251addafcdba399c13.jpeg) ---
**Author:** ![bcawhern1](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/bcawhern1/32/408713_2.png) [@bcawhern1](https://forum.nachi.org/u/bcawhern1)\ **Post date:** [November 18, 2024, 9:46pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/2 "2024-11-18T21:46:28Z")
> **[QuietCool QC CL-2250 Classic Advanced Whole House Fan - Up to 2465 CFM - Two...](https://www.amazon.com/QuietCool-Original-Classic-Fan-Model/dp/B087X7598L?tag=nachi02-20)** > > QuietCool QC CL-2250 Classic Advanced Whole House Fan - Up to 2465 CFM - Two Speed - Covers up to 1,233 SQFT - 10 Year Warranty - Removable Grille - R5 Insulated Dampers - 20ft Power Cord: Ceiling Fans: Amazon.com: Tools & Home Improvement There are variations among the model numbers. Be sure to get that information. Take pictures of all data plates/stickers. ![image](https://global.discourse-cdn.com/internachi/original/4X/c/c/6/cc614d1abd850b9f30520e0685f4390193b68500.jpeg) ---
**Author:** ![mjorge2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mjorge2/32/250241_2.png) [@mjorge2](https://forum.nachi.org/u/mjorge2)\ **Post date:** [November 18, 2024, 9:56pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/3 "2024-11-18T21:56:37Z")
Ok, so what it just draws hot air out of the interior and vents it into the attic? Is that acceptable to vent something like this into the attic? I just thought it was strange that it was installed right next to an air intake. ---
**Author:** ![ruecker](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ruecker/32/357170_2.png) [@ruecker](https://forum.nachi.org/u/ruecker)\ **Post date:** [November 18, 2024, 10:07pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/4 "2024-11-18T22:07:24Z")
> [@mjorge2](#): > > Ok, so what it just draws hot air out of the interior and vents it into the attic?.. That appears to be what they are doing. That would **not** work out good in my area (MN). If you are in a moderate enough climate, it might not be catastrophic, assuming the attic is well vented, but still not best practice. ---
**Author:** ![mwilles](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mwilles/32/181480_2.png) [@mwilles](https://forum.nachi.org/u/mwilles)\ **Post date:** [November 18, 2024, 10:10pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/5 "2024-11-18T22:10:22Z")
It’s a fancy whole house fan. Just inspect it and move on. ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [November 18, 2024, 10:13pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/6 "2024-11-18T22:13:21Z")
> [@mjorge2](#): > > tried to turn it on but **couldn’t hear** or feel any air movement. It **is** called a **Quiet** Cool. lol ---
**Author:** ![tglaze](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/tglaze/32/362210_2.png) [@tglaze](https://forum.nachi.org/u/tglaze)\ **Post date:** [November 18, 2024, 10:17pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/7 "2024-11-18T22:17:42Z")
> [@ruecker](#): > > If you are in a moderate enough climate, it might not be catastrophic, assuming the attic is well vented, but still not best practice. Common to see whole house fans in the South in some older homes (60’s/70’s) Some were installed as to recirculate the air in warmer months by opening windows, screen doors etc. The attic needs to be properly ventilated as you said and the system should be used when the HVAC system off, not at the same time. Probably not the best means to recirculate the air, but it will suck out the smoke when you burn something in the kitchen, then store it in the attic… 🤔 ---
**Author:** ![ruecker](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ruecker/32/357170_2.png) [@ruecker](https://forum.nachi.org/u/ruecker)\ **Post date:** [November 18, 2024, 10:28pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/8 "2024-11-18T22:28:03Z")
> [@tglaze](#): > > Common to see whole house fans in the South in some older homes (60’s/70’s) Some were installed as to recirculate the air in warmer months by opening windows, screen doors etc… I see the occasional one in older homes up here as well. I tell the clients to make sure it is well sealed in the winter. ---
**Author:** ![kleonard](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/kleonard/32/170953_2.png) [@kleonard](https://forum.nachi.org/u/kleonard)\ **Post date:** [November 18, 2024, 10:33pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/9 "2024-11-18T22:33:43Z")
I wouldn’t mind having one in my house. Open the windows and draw in cool air in the morning and blow hot air out of the attic at night. Although here in Ohio I would prefer more than an R-5 insulation rating on the dampers. ---
**Author:** ![bcawhern1](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/bcawhern1/32/408713_2.png) [@bcawhern1](https://forum.nachi.org/u/bcawhern1)\ **Post date:** [November 18, 2024, 11:13pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/10 "2024-11-18T23:13:58Z")
As a child, at night, we crack our windows, position our beds under the window and sleep blissfully cool with the soothing white noise of a whole house fan. Additionally, my mother would “air out” the house at least once a day. It would easily exhaust all stale air in 5 minutes. Energy efficiency was not their strong suit. But fresh air, cool nights and deep sleep were worth the trade off back then. ---
**Author:** ![wkading](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/wkading/32/179353_2.png) [@wkading](https://forum.nachi.org/u/wkading)\ **Post date:** [November 19, 2024, 3:43pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/11 "2024-11-19T15:43:17Z")
Air return is for FAU, Quiet cool is very common a lot found in California since 2015, get used to them especially in two story houses upstairs floors. Don’t run at same time as FAU . Enjoy. ---
**Author:** ![jluttrall](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jluttrall/32/250855_2.png) [@jluttrall](https://forum.nachi.org/u/jluttrall)\ **Post date:** [November 19, 2024, 5:11pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/12 "2024-11-19T17:11:51Z")
Whole hose fans, commonly called “Attic Fans” were a common and desirable appliance in the days before air conditioners. Obviously it depressurizes the entire house and requires windows/doors be opened strategically to be effective. Be careful with gas appliances in the depresurized zones since they will back draft. Not used much now but can still be effective in moderate climates. Humidity is a big factor which is why they have fallen out of favor in most of the humid south. ---
**Author:** ![ryoung7](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ryoung7/32/188798_2.png) [@ryoung7](https://forum.nachi.org/u/ryoung7)\ **Post date:** [November 19, 2024, 5:24pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/13 "2024-11-19T17:24:24Z")
> [@mjorge2](#): > > Is that acceptable to vent something like this into the attic? I just thought it was strange that it was installed right next to an air intake. From what I recall, intakes should be at least 10’ ft away from combustion or plumbing vents and exhaust air outlets. Did you ask the vender? Ask the seller or vender to operate. I would note; inoperable, if it was, the day of the inspection. Suspect clearance from ceiling vent. ---
**Author:** ![lhenderson2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lhenderson2/32/58205_2.png) [@lhenderson2](https://forum.nachi.org/u/lhenderson2)\ **Post date:** [November 19, 2024, 5:53pm UTC](https://forum.nachi.org/t/unknown-ventilation-system/249203/14 "2024-11-19T17:53:33Z")
> [@lkage](#): > > It **is** called a **Quiet** Cool. lol Whole house fans are popular around here. These are pretty quiet but not silent. I always do a subjective analysis of the attic ventilation to determine if it appears adequate to allow the exhaust of all the air being introduced.